1. Field of the Invention
The present invention relates to a lens barrel and an imaging apparatus having the lens barrel.
2. Description of the Related Art
Conventionally, for a zoom lens barrel that is extended in the image-taking state and is retracted in the storage-state, various techniques have been proposed for shortening the dimension (cylinder length) in the optical axis direction in the storage state.
Japanese Patent Laid-Open No. 2004-347615 discloses a technique in which a lens barrel is provided that enables the cylinder length thereof to be shortened by opening a lens shutter in the storage state so as to insert a lens group into an aperture; and a camera provided with such lens barrel.
Also, as in Japanese Patent Laid-Open No. 2004-347615 described above, Japanese Patent No. 3496667 discloses a technique for shortening the cylinder length in the storage state as well as protecting an image sensor and a color filter by preventing them from being exposed by external light using a lens barrier as a light shielding member.
However, the conventional technique disclosed in Japanese Patent Laid-Open No. 2004-347615 does not take into account the deterioration of such an image sensor, color filter, and the like that is caused by external light that reaches the image sensor and the color filter in the storage state. Also, the conventional technique disclosed in Japanese Patent No. 3496667 cannot achieve perfect light shielding with a lens barrier that is employed as a light shielding member in the storage state. As a result, sufficient light shielding cannot be obtained even when a lens barrier provided at the tip of the barrel is in a closed state. The performance degradation of the image sensor and the optical components provided on the front side of the image sensor may occur because light that slightly enters from the space of the lens barrier reaches the image sensor.